Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device, and in particular, relates to maintenance of a semiconductor manufacturing apparatus.
Description of the Related Art
The semiconductor manufacturing apparatuses, such as a dry etching apparatus, a CVD apparatus (CVD: Chemical Vapor Deposition), and a sputtering apparatus, that are used in a semiconductor manufacturing line each have a processing chamber in which a semiconductor wafer is processed in vacuum, and each mount a semiconductor wafer on a stage (a lower part electrode) in the processing chamber, where various processing such as dry etching by plasma is performed.
A through hole that penetrates from the front side to the back side is provided in the stage in the processing chamber and the processing chamber has a structure in which a semiconductor wafer is delivered between the wafer conveying arm and the stage by a wafer lift pin moving up and down in the inside of the through hole.
In these semiconductor manufacturing apparatuses, when processing a semiconductor wafer inside the processing chamber, reaction product is generated, and the reaction product adheres to the inside of the through hole (lift pin hole) of the stage through which the wafer lift pin moves up and down and also to a support part (lift pin gripper) of the wafer lift pin.
When deposition of the reaction product inside the lift pin hole increases, there is a possibility that the lift pin may be caught by the reaction product and the lift pin may escape from a lift pin supporting part. Moreover, when an amount of deposition of the reaction product onto the lift pin supporting part increases, slidability of the lift pin supporting part gets worse, and there is a concern about lift pin omission similarly.
Then, cleaning that removes periodically the reaction product adhering to the inside of the lift pin hole and the lift pin supporting part becomes required, but in order to clean these portions, the stage (lower electrode) must be decomposed, which needs much labor and apparatus halt time for the cleaning.
As a method for removing the reaction product inside the lift pin hole without disassembling a stage (lower electrode), a method that uses a cleaning tool like that of Patent Document 1 is considered, for example. Patent Document 1 is related to an interdental toothbrush for removing dirt between teeth of a human body.
[Patent document 1] Japanese Patent Application Laid-Open No. Hei 11(1999)-137577
When a cleaning tool of Patent Document 1 described above is tried to be used for cleaning the lift pin hole of a semiconductor manufacturing apparatus, since the cleaning tool does not have sufficient strength for removing reaction product inside the lift pin hole, it is difficult to remove the reaction product effectively. Moreover, it is also difficult to prevent the removed reaction product from falling to the lower part of the lift pin hole. Furthermore, the cleaning tool of Patent Document 1 is used as an interdental brush originally, and if it is used in cleaning of the semiconductor manufacturing apparatus, there will be a possibility of becoming a cause of contamination.
Other problems and new features will become clear from description and accompanying drawings of this specification.